Contents Wiring diagrams Section: Automatic Trans All sections

Shift Lock Control System: Other Chevrolet Silverado 3500

Automatic Trans 2 illustrations ~531 words

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Shift Lever Does Not Move with Brake Pedal Depressed

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics Connector End View Reference: Automatic Transmission Shift Lock Control Connector End Views , Automatic Transmission Related Connector End Views or Automatic Transmission Related Connector End Views DEFINITION: Transmission shift lever will not move out of the PARK position with the ignition ON and the brake pedal pressed.
1Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and all the necessary inspection?Go to Step 2Go to Symptoms - Automatic Transmission Shift Lock Control
2Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 3
3Turn OFF the ignition. Disconnect the automatic transmission shift lock control switch. Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Attempt to move the transmission shift lever out of the PARK position. Does the transmission shift lever move out of the PARK position?Go to Step 6Go to Step 4
4Turn OFF the ignition. Disconnect the automatic transmission shift lock control solenoid. Turn ON the ignition, with the engine OFF Press and hold the brake pedal. Attempt to move the transmission shift lever out of the PARK position. Does the transmission shift lever move out of the PARK position?Go to Step 7Go to Step 5
5Inspect for poor connections at the harness connector of the automatic transmission shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 9
6Inspect for poor connections at the harness connector of the automatic transmission shift lock control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 8
7Repair the short to battery positive voltage in the A/T shift lock control solenoid supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 10
8Replace the automatic transmission shift lock control switch. Refer to Stop Lamp Switch Replacement in Lighting Systems. Did you complete the replacement?Go to Step 10
9Replace the automatic transmission shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement . Did you complete the replacement?Go to Step 10
10Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Shift Lever Does Not Move with Brake Pedal Depressed

Shift Lever Can Be Moved without Brake Pedal Depressed (w/o Allison Transmission)

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics Connector End View Reference: Automatic Transmission Shift Lock Control Connector End Views , Automatic Transmission Related Connector End Views or Automatic Transmission Related Connector End Views DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition ON and the brake pedal not pressed.
1Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and all the necessary inspections?Go to Step 2Go to Symptoms - Automatic Transmission Shift Lock Control
2Apply the parking brake and block the wheels. Turn ON, the ignition, with the engine OFF. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Turn OFF the ignition. Ensure transmission shift lever is in the PARK position. Connect a test lamp between the A/T shift lock switch supply voltage circuit at the BTSI fuse and a good ground Turn ON the ignition, with the engine OFF. Does the test lamp illuminate?Go to Step 4Go to Step 8
4Connect a test lamp between the A/T shift lock switch supply voltage circuit at the automatic transmission shift lock control switch and a good ground Does the test lamp illuminate?Go to Step 5Go to Step 14
5Connect a test lamp between the A/T shift lock solenoid control circuit at the automatic transmission shift lock control switch and a good ground. Press and release the brake pedal several times. Does the test lamp turn ON and OFF with the brake pedal?Go to Step 6Go to Step 11
6Connect a test lamp between the automatic transmission shift lock control solenoid supply voltage circuit at the automatic transmission shift lock control solenoid and a good ground. Does the test lamp illuminate?Go to Step 7Go to Step 15
7Test the automatic transmission shift lock control solenoid ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 20Go to Step 12
8Turn OFF the ignition Disconnect the park/neutral position switch connector. Connect a test lamp between the ignition 1 voltage circuit of the park/neutral position switch and a good ground. Turn ON the ignition, with the engine OFF. Does the test lamp illuminate?Go to Step 9Go to Step 13
9Turn OFF the ignition Connect a 10 amp fused jumper between the ignition 1 voltage circuit of the park/neutral position switch and the park/neutral position switch park signal circuit at the park/neutral position switch connector. Connect a test lamp between the A/T shift lock switch supply circuit at the BTSI fuse and a good ground. Turn ON the ignition, with the engine OFF. Does the test lamp illuminate?Go to Step 10Go to Step 16
10Inspect for proper park/neutral position switch adjustment. Refer to Park/Neutral Position Switch Adjustment with 4L60-E transmission or Park/Neutral Position Switch Adjustment with 4L80-E transmission. Inspect for poor connections at the harness connector of the park/neutral position switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 20Go to Step 17
11Inspect for poor connections at the harness connector of the automatic transmission shift lock control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 20Go to Step 18
12Inspect for poor connections at the harness connector automatic transmission shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 20Go to Step 19
13Repair the open or short in the ignition 1 voltage circuit of the park/neutral position switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 20
14Repair the open or short in the A/T shift lock switch supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 20
15Repair the open in the A/T shift lock control solenoid supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 20
16Repair the open or short in the park/neutral position switch park signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 20
17Replace the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement with 4L60-E transmission or Park/Neutral Position Switch Replacement with 4L80-E transmission. Did you complete the replacement?Go to Step 20
18Replace the automatic transmission shift lock control switch. Refer to Stop Lamp Switch Replacement in Lighting Systems. Did you complete the replacement?Go to Step 20
19Replace the automatic transmission shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement . Did you complete the replacement?Go to Step 20
20Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Shift Lever Can Be Moved without Brake Pedal Depressed (w/o Allison Transmission)

Scheme 600

Scheme 600: Removal Procedure
  1. Disable the SIR system. Refer to «SIR Disabling and Enabling Zone 3»(ref-184143-S31454458592005082200000) in SIR.
  2. Remove the body control module (BCM). Refer to «Body Control Module Replacement»(ref-184112-S25205980332005082200000) in Body Control System.
  3. Put the shift lever clevis into the neutral position.
  4. Disconnect the electrical connector.
  5. Using a small screwdriver, pry the automatic transmission shift lock control actuator away from the steering column jacket and the cable shift cam.
  6. Remove the shift lock control actuator.

Scheme 601

Scheme 601
  1. Firmly install the shift lock control actuator onto the steering column jacket and the cable shift cam.
  2. Connect the electrical connector.
  3. Adjust the shift lock control actuator (with the shift lever clevis in the neutral position) in the following way: Pull out the tab (1) on the adjuster block side (2) of the shift lock control actuator. Press on the adjuster block (2) to compress the internal adjuster spring which disengages the adjuster teeth. Slide the adjuster block (2) as far away from the actuator as possible. Lock the adjuster block (2) in place by pushing in on the tab (1).
  4. Inspect the shift lock control actuator for the following items: The shift lock control actuator must lock the shift lever clevis when the shift lever clevis is put into the park position. Depress the brake pedal to move the shift lever out of the park position. The actuator will be energized. Readjust the shift lock control actuator if needed.
  5. Install the BCM. Refer to «Body Control Module Replacement»(ref-184112-S25205980332005082200000) in Body Control System.
  6. Enable the SIR system. Refer to «SIR Disabling and Enabling Zone 3»(ref-184143-S31454458592005082200000) in SIR.

The automatic transmission shift lock control is a safety device that prevents an inadvertent shift out of PARK when the ignition is ON. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components

  1. The automatic transmission shift lock control solenoid.
  2. The automatic transmission shift lock control switch.
  3. The park/neutral position switch.

With the ignition in the ON position, battery positive voltage is supplied to the park/neutral position switch. When the transmission is in the PARK position the contacts in the park/neutral position switch are closed. This allows current to flow through the switch to the automatic transmission shift lock control switch. The circuit continues through the normally-closed switch to the automatic transmission shift lock control solenoid. The automatic transmission shift lock control solenoid is permanently grounded. This energizes the automatic transmission shift lock control solenoid, locking the shift linkage in the PARK position. When the driver presses the brake pedal the contacts in the automatic transmission shift lock control switch open, causing the automatic transmission shift lock control solenoid to release. This allows the shift lever to move from the PARK position.